北斗二代信号的捕获跟踪算法与抗干扰性能研究

发布时间：2018-08-24 17:55

【摘要】：载波、伪码的捕获跟踪是衡量北斗接收机性能的关键指标之一。然而由于北斗系统比GPS等有更长的伪随机序列，当采用传统捕获方法时，它将耗费更长的捕获时间和更多的资源。本文采用基于差分匹配滤波器的并行分集结构，利用匹配滤波器将载波-伪码的二维搜索化解为载波的一维搜索，并通过差分滤波器和并行分集的理论在并行捕获中资源的复用进一步降低资源的消耗、缩短捕获时间。针对北斗信号的特点，仿照GPS信号发射模型对北斗信号的产生进行建模。基于多普勒频移对相关增益影响的特性，对北斗信号的捕获算法进行了设计与仿真。对接收机在均匀频带干扰和窄带干扰条件的抗干扰性能进行了评估。结果表明：本文中所采用的捕获结构在复杂度上低于常用的捕获算法，硬件运算复杂度并不随过采样倍数的增加而增加。在干信比低于30dB的情况下，，接收机在均匀频带干扰和窄带干扰的条件下能在很低的误码率下工作。
[Abstract]:Acquisition and tracking of carrier and pseudo code is one of the key indexes to evaluate the performance of Beidou receiver. However, Beidou system has longer pseudorandom sequences than GPS and so on. When the traditional acquisition method is adopted, it will consume longer acquisition time and more resources. In this paper, the parallel diversity structure based on differential matched filter is used to resolve the two-dimensional search of carrier and pseudo code into one dimensional search of carrier. Furthermore, the reuse of resources in parallel acquisition based on the theory of differential filter and parallel diversity can further reduce the consumption of resources and shorten the acquisition time. According to the characteristics of Beidou signal, the model of Beidou signal is modeled according to the GPS signal transmission model. Based on the influence of Doppler frequency shift on correlation gain, the acquisition algorithm of Beidou signal is designed and simulated. The anti-jamming performance of the receiver under uniform band interference and narrow band interference is evaluated. The results show that the complexity of the acquisition structure used in this paper is lower than that of the conventional acquisition algorithms, and the hardware complexity does not increase with the increase of oversampling times. When the signal ratio is lower than 30dB, the receiver can work under the condition of uniform band interference and narrow band interference at very low bit error rate (BER).
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN96.1

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